It does not need to be explosion proof.
Think this through.
The gases you are working with will have already been burned so there will not be anything exploding unless you turn on the gas and then don't light the torch at all.
There are several threads here about ventilation and you are going to have to read through them and learn all the details involved. You only have to learn them once and when you have your system setup you won't have to think much about it after ward.
There is another forum at Art Glass Answers with in depth details on ventilation that Robert Simmons has pointed us to from this LE thread
http://www.lampworketc.com/forums/sh...d.php?t=271063.
The author of that thread is Dale Meisenheimer and he has very detailed diagrams and the numbers you will want to use to figure out what you need at this web site
http://www.artglassanswers.com/forum...a316eedc031ae7
Take your time and think through all the details. It is not hard to do but your safety requires that you understand what you are doing. Kind of like learning to drive a car, once you get it straight in your mind it will become second nature to you.